Light- and Electron-microscopic Investigation of Anp-like Immunoreactivity in Aorta, Carotid Artery and Cultured Cardiac Myocytes of the Rat

In the present investigation we have sought for atrial natriuretic peptide (ANP) -like immunoreactivity in aorta, carotid artery, cultured aortic cells and cultured cardiac myocytes of the rat at the light- and electron-microscopic level using antibodies directed against atriopeptin II (5-27). Aortic and carotid aretery sections as well as cultured aortic cells did not show any ANP-specific immunoreactivity, preabsorbable by atriopeptin II or a-rat ANP (1-28). Cultured cardiac myocytes could be shown to contain ANP granules and secrete immunoreactive ANP.